$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
7.85
\begin{equation} \begin{gathered}\label{equation:spaces-locally-cartesian-closed} \xymatrix { A \ar [r] \ar [d] & M \ar [d] \\ B \ar@ {-->}[ur] \ar [r] & S } \end{gathered} \end{equation}